Errata - in the original version of the pattern, there was a typo in rows 15 & 16 of the Heel section. This has been corrected in the current version of the pattern available for download. Here is how these two rows should read:

Row 15: Sl 1 pwise wyib, k22, sl next st to right ndl, pass next to last st on right ndl over the slipped st, turn. Row 16: Sl 1 pwise wyif, p22, ssp (wrap with its st), sl next st to right ndl, pass next to last st on right ndl over the slipped st, turn.